Abstract
About half of the sphingomyelin content of fresh and ATP-depleted chicken erythrocytes is hydrolysed by sphingomyelinase. Removal of sphingomyelin exposes the rest of the membrane phospholipids to hydrolysis by phospholipase C only in ATP-depleted but not in fresh cells. Addition of both sphingomyelinase and phospholipase C to ATP-depleted cells causes about 60-70% hydrolysis of the total phospholipids accompanied by extensive (90%) hemolysis. The phospholipids of toad erythrocytes are partially available to phospholipase C activity in fresh cells (17-25% hydrolysis) without prior sphingomyelinase treatment. However, in ATP-depleted toad cells phospholipase C hydrolyses 66% of phospholipids and causes extensive lysis. Treatment of either fresh or ATP-depleted toad erythrocytes by sphingomyelinase together with phospholipase C induces hydrolysis of most of the phospholipids with complete lysis. Restoration of ATP to ATP-depleted cells endows them with resistance to the attack of phospholipase C. The correlation between changes in ATP level and membrane organization as revealed by increased susceptibility toward phospholipase is discussed.
Original language | English |
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Pages (from-to) | 65-72 |
Number of pages | 8 |
Journal | Biochimica et Biophysica Acta - Biomembranes |
Volume | 382 |
Issue number | 1 |
DOIs | |
State | Published - 28 Feb 1975 |